一种新型电校准光辐射探测器特性的研究

Characterization of a Newly Developed Electrically Calibrated Radiometer

对一种新型电校准辐射计的面响应不均匀性、线性和绝对响应度等特性进行了研究。在 0 .7～ 750 μW范围内测得其线性度优于 0 .5%。面响应不均匀性的测量是利用小的激光光斑在探测器的灵敏面进行二维扫描。在探测器的主要灵敏面内 ,相对响应度与到探测器中心的距离表现为二次曲面关系。本文对不同光斑大小、光束横截面上不同功率分布以及光斑入射到探测器表面的不同位置引起的测量误差进行了分析和研究。给出了是否需要修正的判椐和需要修正时所应采用的修正方法 ,这种方法也适用于其它类型的电校准辐射计 ,利用该修正方法可以显著降低测量不确定度。实验考查了面响应不均匀性的影响 ,实验结果证明了修正方法的正确性。

The spatial non-uniformity, linearity and absolute responsivity of a newly developed electrically calibrated radiometer (ECR) are characterized in this work. Spatial non-uniformity is measured by applying a small laser spot scanning across the detector sensitive area. The responsivity over the sensitive area has a quadratic relation with distance to detector center within the main sensitive area. The errors generated by different beam sizes,different beam power distributions and different beam positions impinging on the detector are analyzed and investigated. Criterion for necessity of a correction and correction method needed are given, which are also suitable for other kinds of electrically calibrated radiometers (ECRs). Significant reduction of measurement uncertainty is achieved by applying the correction method. The authors investigated experimentally the influence of spatial non-uniformity as well; the results proved the correction method.